Does dynamic navigation system preserve more dentine? - A systematic review.

OBJECTIVE: This systematic review aims to comparatively analyse the amount of dentin removal by free hand and static guided endodontics with dynamic navigation system (DNS) in endodontic access cavity preparation. METHODS: The systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Based on the structured PICO framework of "Comparative evaluation of dynamic navigation system (I) to freehand (C) and static guided endodontics (C) in endodontic access cavity preparation on the preservation of tooth structure (O) when assessed on permanent human teeth (P)", the keywords were formulated and the articles were retrieved from three databases namely PubMed, Scopus and Embase, based on the keywords from the time of inception of DNS till June 2023. The risk of bias assessment was done using a modified Joanne Briggs Institute checklist, which evaluated domains such as randomisation, sample size, image acquisition using CBCT, angulation, accuracy and time taken. As the data was heterogenous, a quantitative meta-analysis was not performed. RESULTS: Initially, 174 articles were retrieved from the three databases, 30 duplicates were removed, after title check 108 articles were excluded and following abstract check only 10 articles qualified for full text analysis. On reviewing the 10 full text articles, 5 articles were excluded and the remaining 5 articles were subjected to the risk of bias analysis which showed that 2 articles displayed low risk of bias and three articles showed high risk of bias. The RoB analysis revealed that only 2 studies evaluated the preservation of dentin in terms of accuracy, angulation and time taken proving the increased precision with minimal loss of tooth structure using DNS. In both the studies, DNS proved to be superior to free hand technique in terms of precision, accuracy and efficiency in locating the canals during access cavity preparation with maximal preservation of tooth structure. CONCLUSION: With the minimal literature evidences, the present systematic review highlights maximal preservation of dentin using DNS. However, further invitro and invivo studies comparing the free hand, static guided endodontics to DNS must be carried out for its translation into clinical practice. CLINICAL SIGNIFICANCE: Dynamic navigation system provides maximal preservation of dentin during access cavity preparation.

Physico-chemical and biological characterization of synthetic and eggshell derived nanohydroxyapatite/carboxymethyl chitosan composites for pulp-dentin tissue engineering.

Hybrid nanohydroxyapatite/carboxymethyl chitosan (nHAp-CMC) scaffolds have garnered significant attention in the field of regenerative engineering. The current study comparatively analyzed the physicochemical and biological properties of synthetic nanohydroxyapatite (SnHA)- and eggshell-sourced nanohydroxyapatite (EnHA)- based CMC biocomposites for pulp-dentin regeneration. EnHA and CMC were synthesized through a chemical process, whereas SnHA was commercially obtained. Composite scaffolds of SnHA-CMC and EnHA-CMC (1:5 w/w) were prepared using freeze-drying method. All biomaterials were characterized by FTIR, micro-Raman, XRD, HRSEM-EDX, and TEM analyses, and their in vitro bioactivity was assessed by immersing them in simulated body fluid for 21 days. The biological properties of the composite scaffolds were evaluated by assessing cytocompatibility using MTT assay and biomineralization potential by analyzing the odontogenic gene expressions (ALP, DSPP, DMP-1 and VEGF) in human dental pulp stem cells (DPSCs) using RT-qPCR method. Characterization studies revealed that EnHA displayed higher crystallinity and superior surface morphology compared to SnHA. The composite scaffolds showed a highly interconnected porous microstructure with pore sizes ranging between 60 and 220 µm, ideal for cell seeding. All tested materials, SnHA, EnHA, and their respective composites, displayed high cytocompatibility, increased ALP activity and degree of mineralization with significant upregulation of odontogenic-related genes on DPSCs (p < 0.05). Nevertheless, the odontogenic differentiation potential of EnHA-CMC on DPSCs was significantly higher when compared to SnHA-CMC. The findings from this study highlight the potential of EnHA-CMC as a promising candidate for pulp-dentin engineering.

Biomimetic dentin remineralization using eggshell derived nanohydroxyapatite with and without carboxymethyl chitosan - An in vitro study.

The objective of this study was to evaluate the synergistic effect of eggshell-derived nanohydroxyapatite (EnHA) and carboxymethyl chitosan (CMC) in remineralizing artificially induced dentinal lesions. EnHA and CMC were synthesized using simple chemical processes and characterized using FTIR, XRD, HRSEM-EDX, TEM, DLS and TGA/DTA analyses. A total of 64 pre-demineralized coronal dentin specimens were randomly subjected to following treatments (n = 16):artificial saliva (AS), EnHA, CMC, and EnHA-CMC, followed by pH cycling for 7 days. HRSEM-EDX, Vickers-indenter, and micro-Raman analyses were used to assess surface-topography, microhardness, and chemical analysis, respectively. All tested materials demonstrated non-cytotoxicity when assessed on hDPSCs using MTT assay. FTIR, XRD and thermal analyses confirmed the characteristics of both EnHA and CMC. EnHA showed irregular rod-shaped nanoparticles (30-70 nm) with the presence of Ca,P,Na, and Mg ions. Dentin treated with EnHA-CMC exhibited complete tubular occlusion and highest microhardness whereas the AS group revealed the least mineral deposits (p < 0.05). No significant differences were observed between EnHA and CMC groups (p > 0.05). In addition, molecular conformation analysis revealed peak intensities in collagen's polypeptide chains in dentin treated with CMC and EnHA-CMC, whereas other groups showed poor collagen stability. The results highlighted that EnHA-CMC aided in rapid and effective biomineralization, suggesting its potential as a therapeutic solution for treating dentin caries.

Characterisation and evaluation of physical properties of AH-Plus sealer with and without the incorporation of petasin, pachymic acid, curcumin and shilajit-an invitro study.

BACKGROUND: AH Plus, an epoxy resin-based sealer, is widely used in endodontic practice, owing to its good physical properties that confers longstanding dimensional stability and good adhesion to dentin. Nevertheless, its propensity to trigger inflammation, especially in its freshly mixed state, has been extensively documented. Phytochemicals such as Petasin, Pachymic acid, Curcumin, and Shilajit are known for their anti-inflammatory and analgesic effects. This study aimed to analyze and determine the effect of these natural products on the physical properties of AH Plus sealer when incorporated with the sealer. METHODS: AH Plus (AHR) sealer was mixed with 10% petasin, 0.75% pachymic, 0.5% and 6%shilajit to obtain AHP, AHA, AHC and AHS in the ratio of 10:1 and 5:1 respectively. Five samples of each material were assessed for setting time, solubility, flow, and dimensional stability in accordance with the ISO 6876:2012 standardization. Sealers were characterized through scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Statistical evaluation involved the Kolmogorov-Smirnov and Shapiro-Wilks tests for normality and the one-way ANOVA test for analysis. RESULTS: In this investigation, the characterisation analysis revealed a relatively similar microstructure in all the experimental root canal sealers. All experimental groups, excluding the control group, exhibited an increase in flow ranging from 11.9 to 31.4% at a 10:1 ratio. Similarly, for the 5:1 ratio, the increase ranged from 12.02 to 31.83%. In terms of dimensional stability, all groups at the 10:1 ratio showed a decrease compared to the control group. The addition of natural agents to AHR in 10:1 ratio led to a reduction in setting time by 8.9-31.6%, and at a 5:1 ratio, the reduction ranged from 8.1 to 31.5%. However, regarding solubility, the addition of natural agents did not induce any significant alterations. CONCLUSION: Based on the results of this study, it can be concluded that all tested root canal sealers exhibited properties that met the acceptable criteria outlined in the ISO 6876:2012 standardization.

Effect of strontium fluorophosphate bioactive glass on color, microhardness and surface roughness of bleached enamel.

BACKGROUND: Undesirable effects of tooth bleaching can alter the biomechanical properties of enamel. OBJECTIVE: To determine the influence of strontium fluorophosphate bioactive glass (Sr-FPG) on color, microhardness and surface roughness of enamel bleached with 35% hydrogen peroxide. METHODS: The labial enamel of 36 extracted intact human anterior teeth were divided into 3 groups (n= 12), group 1 (HP): bleaching with 35% hydrogen peroxide only, group 2 (Sr-HP): bleaching with Sr-FPG incorporated 35% hydrogen peroxide and group 3 (HP-SrFPG): bleaching with 35% hydrogen peroxide followed by remineralization with Sr-FPG. Four consecutive eight-minute applications of the bleaching gel were done twice in all the groups. Color change (ΔE), microhardness and surface roughness were evaluated at baseline, post-bleaching and post-remineralization using spectrophotometer, Vickers hardness tester and profilometric analysis respectively. RESULTS: The mean ΔE among the groups was statistically similar (p> 0.05). Bleaching with HP significantly reduced microhardness (p< 0.05), whereas bleaching with Sr-HP and HP-SrFPG did not (p> 0.05). Post-bleaching microhardness in Sr-HP was significantly higher than HP-SrFPG (p< 0.05). An increased surface roughness was seen in Sr-HP bleached samples (p< 0.05). CONCLUSION: The addition of Sr-FPG to hydrogen peroxide significantly improved enamel microhardness than its use post-bleaching. An increase in surface roughness was seen post-bleaching with HP and Sr-HP.

Comparative evaluation of effect of nisin-incorporated ethylenediamine tetraacetic acid and MTAD on endodontic biofilm eradication, smear layer removal, and depth of sealer penetration.

OBJECTIVES: To comparatively evaluate the nisin-incorporated ethylenediamine tetraacetic acid (N-EDTA) and MTAD on cytotoxicity, endodontic biofilm eradication potential, smear layer removal ability, and sealer penetration depth. MATERIALS AND METHODS: N-EDTA was prepared and characterized using high-performance liquid chromatography (HPLC). Minimum inhibitory, minimum bactericidal, and minimum biofilm inhibitory concentration (MBC, MIC, and MBIC) were determined on Enterococcus faecalis (E. faecalis) strain. The cytocompatibility of N-EDTA and MTAD was evaluated using 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay. Dentin specimens (n = 88 for antibacterial analysis, n = 170 for sealer penetration depth) were prepared and subjected to the classical irrigating strategy and obturation, respectively. The scanning electron microscopic evaluation (SEM) was done for the evaluation of biofilm disruption and smear layer removal. Confocal laser scanning microscopy (CLSM) evaluation was done for determining percentage of bacterial viability and sealer penetration depth. Statistical analysis of one-way ANOVA and Tukey's HSD post hoc tests for bacterial viability and Kruskal-Wallis test and Mann-Whitney test for smear layer removal and depth of penetration were done with the significance level set at p < 0.05. RESULTS: MTAD and N-EDTA showed cytocompatibility without any statistical differences from each other. For N-EDTA, the MIC and MBC values were 12.5 µg/ml (1:8), and MBIC values were 36 µg/ml. Biofilm disruption and killed bacterial percentage of N-EDTA was statistically higher than MTAD, whereas both the materials showed similar efficacy in the removal of the smear layer and sealer penetration depth. CONCLUSION: N-EDTA had negligible cytotoxicity with similar smear layer removal ability, sealer penetration, and better antibiofilm potential than MTAD. CLINICAL RELEVANCE: N-EDTA can serve as a viable alternative endodontic irrigant.

Bioburden assessment of necrotic teeth disinfected with sodium hypochlorite, diode laser, and photodynamic therapy using flow cytometry-a randomized double-blinded clinical trial.

This study aimed to comparatively evaluate the disinfecting potential of sodium hypochlorite, diode laser, and photodynamic therapy in non-vital teeth with or without periapical rarefaction. Forty-five patients with the diagnosis of pulp necrosis with apical rarefaction were randomly assigned to three groups (n = 15) based on the disinfection protocol. Access cavities were prepared and pre-instrumentation microbial samples were taken using a paper point. Working length determination followed by cleaning and shaping with rotary files was performed. The canals were lubricated with ethylenediaminetetraacetic acid (EDTA) during instrumentation and finally rinsed with copious amounts of saline. Canals in group 1 were irrigated with 5 mL of 5.25% NaOCl, those in group 2 received irradiation with 808-nm diode laser (30 s, 7W), and those in group 3 were soaked with methylene blue photosensitizer (5 min) before irradiation with 660-nm diode laser (3 min). Post-disinfection microbial samples were collected using a paper point. Pre- and post-disinfection live bacterial counts were analyzed using a flow cytometer. The data were statistically analyzed using one-way ANOVA and Student's t-test. Comparison of pre-instrumentation mean live bacterial count showed no significant difference between the groups (p > 0.05). The mean live bacterial count post-disinfection was 41.07%, 46.99%, and 34.45% in groups 1-3 respectively. A significant reduction in the bacterial count was seen following disinfection in all the groups (p < 0.05). It can be concluded that both diode laser and photodynamic therapy were equally effective as 5.25% NaOCl in reducing the bioburden in root canals. TRIAL REGISTRATION: CTRI/2018/03/012667.

Development of cobalt-incorporated chitosan scaffold for regenerative potential in human dental pulp stem cells: An in vitro study.

The aim of the study was to comparatively evaluate chitosan and Cobalt incorporated chitosan (CoCH) scaffold at varying concentrations in terms of their material characteristics, cytotoxicity and cell adhesion potential. In the present study, cobalt incorporated chitosan scaffolds at varying concentrations were prepared and dried. The synthesised scaffolds were characterised using XRD, FTIR, SEM-EDX and BET which revealed amorphous, porous surface of CoCH scaffolds and FTIR analysis showed the complexation confirming the chelation of cobalt with chitosan. The experimental scaffolds proved to be non-cytotoxic when compared to chitosan scaffolds on XTT analysis. Cell-seeding assay revealed enhanced adherence of hDPSCs to CoCH scaffold at 1:1 ratio in the concentration of 100 mL of 100 µmol/L cobalt chloride solution in 100mL of 2% chitosan solution, when compared to other groups. The results highlighted that 100 µmol/L concentration of cobalt chloride when incorporated in 1:1 ratio into 2 % CH solution yields a promising porous, biocompatible scaffold with enhanced cellular adhesion for dentin-pulp regeneration.

Deciphering the role of Saliva in COVID 19: A global cross-sectional study on the knowledge, awareness and perception among dentists.

OBJECTIVES: The global pandemic outbreak of the coronavirus has instilled the quest amongst researchers on the expedited need for the early detection of viral load. Saliva is a complex oral biological fluid which not only causes the disease transmission but can be an effective alternative sample for detection of SARS-CoV2. This provides an ideal opportunity for dentists to be the frontline healthcare professionals who can collect the salivary samples; however the awareness of this amongst dentists is uncertain. Hence the aim of this survey was to evaluate the knowledge, perception and awareness of the role of saliva in detecting the SARS-CoV2 among dentists worldwide. METHODS: The online questionnaire comprising of 19 questions was shared to 1100 dentists worldwide and a total of 720 responses was collected. The data was tabulated, statistically analysed using the non- parametric Kruskal-Wallis test (p < 0.05). Based on the principal component analysis, 4 components (knowledge about virus transmission, perception about SARS-CoV2 virus, awareness on the sample collection and knowledge about prevention of the virus) were obtained which was compared with the 3 independent variables (years of clinical experience, occupation and region). RESULTS: A statistically significant difference was observed in the awareness quotient amongst the dentists with 0-5 years and greater than 20 years of clinical experience. In terms of the occupation, a significant difference was noted when comparing the postgraduate students to practitioners knowledge about the virus transmission. A highly significant difference was seen on comparing academicians and postgraduate students and also between academicians and practitioners. No significant difference was evidenced amongst the different regions, however the mean score was in the range of 3-3.44. CONCLUSION: This survey highlights the deficiency in the knowledge, perception and awareness among dentists worldwide.

Effect of Polydopamine on Bonding Characteristics of Mineral Trioxide Aggregate to Resin Composite.

OBJECTIVE: The success of vital pulp therapy is crucial to preserve the integrity of the teeth and to enable an uninterrupted root formation in a young permanent tooth. This warrants placement of an intact permanent seal immediately in contact with the pulp capping material. Mineral trioxide aggregate (MTA) sets by hydration and deters placement of an immediate permanent resin composite restoration over it. The aim of this in vitro study is to evaluate the wettability, surface morphology and shear bond strength (SBS) of polydopamine (PDA)-pretreated MTA to resin composite (RC). METHODS: The contact angle (CA) and morphological changes caused by self-etch (SE) adhesive on untreated and PDA-pretreated MTA was analyzed using contact angle meter and scanning electron microscope (SEM) respectively. To evaluate SBS, 144 MTA samples were prepared using a custom-made mold of 5 mm diameter and 3 mm height. The samples were randomly divided into two groups of 72 samples each based on whether their surface was pretreated with PDA or not. Under each group, nano-hybrid RC restoration was done either immediately or after a delay of 3 h, 24 h and 96 h. SBS of the MTA/resin composite assembly was tested in a universal testing machine. CA values were analyzed using One-way analysis of variance and Games-Howell Post Hoc test. Mann-Whitney test and Friedman post-hoc Dunn test were used to analyze SBS values. RESULTS: SE adhesive made a significantly lesser mean CA with PDA-pretreated MTA (27.20°+-2.28) compared to untreated MTA (34.22°+-1.45, p<0.05). SEM micrographs showed that while etching with SE primer eroded the surface characteristics, PDA coating minimized the erosive effect of the acidic primer and preserved the original crystalline plate-like structure of MTA. At all tested time intervals, PDA pretreatment significantly increased the SBS of MTA to RC, compared to untreated control. Immediate bond strength of PDA pretreated MTA (26.30+-7.60 MPa) was equivalent to the SBS value achieved at 96 h with untreated MTA (27.82+-2.96 MPa). CONCLUSION: Within the limitations of this in vitro study, it can be concluded that PDA pretreatment of MTA surface improved its wettability, prevented loss of surface integrity following etching and increased the SBS of RC to MTA. (EEJ-2022-11-144).

Comparative evaluation of different instrument kinematics on contact percentage, dentin removal and apical debris extrusion in oval canals.

The aim of this study was to compare four different instrument kinematics in oval canals. Distal root of sixty extracted first mandibular molars with single oval canal were allocated randomly to four groups (n = 15) namely protaper universal [PTU] (Rotary), self-adjusting file [SAF] (Adaptive), TruShape [TS] (Rotary) and WaveOne [WO] (Reciprocating). The percentage of untouched and touched surfaces of the root canal was evaluated using micro-computed tomography (MCT). Pre- and post-instrumentation weight was assessed using digital microbalance for determining the amount of dentin removed and apical extrusion of debris. The results were tabulated, and their mean difference was statistically analysed using one-way ANOVA and Tukey's HSD test. PTU and SAF exhibited significantly less mean percentage of untouched surface compared to TS. TS files removed less dentin and extruded less debris in long oval canals.

Oyster shell-derived nano-hydroxyapatite and proanthocyanidin pretreatment on dentinal tubule occlusion and permeability before and after acid challenge-an in vitro study.

This in vitro study evaluated the dentinal tubule occlusion (TO), depth of penetration (DoP), and dentin permeability (DP) of oyster shell-derived nanohydroxyapatite (os-nHAp) with and without 15% proanthocyanidin (PA) pretreatment. os-nHAp was synthesized via the precipitation method and it was characterized. The morphology and particle size of os-nHAp were analyzed using a high-resolution transmission electron microscope (HRTEM). Cytotoxicity of os-nHAp, PA/os-nHAp, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) was assessed by (3-(4,5-dimethythiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT) assay using human osteosarcoma (MG-63) cell line. One hundred and ninety-seven dentin discs of 3 mm thickness were prepared from the crown portion of extracted human teeth. The dentinal surfaces of the discs were etched for 2 min with 6% citric acid to simulate dentin hypersensitivity. Five discs were randomly selected and the patency of dentinal tubules was confirmed using a scanning electron microscope (SEM). The remaining 192 discs were divided into four groups (n = 48) depending on the type of remineralization as follows: group 1: os-nHAp, group 2: PA/os-nHAp, group 3: CPP-ACP, and group 4: no treatment. The remineralization protocol was followed for 21 days. Out of the 48 dentin discs in each group, 32 discs were used to evaluate dentinal tubule occlusion (TO) and depth of penetration (DoP) using SEM. The remaining 16 discs were subjected to an assessment of dentin permeability (DP) using a hydraulic conductance model. TO, DoP and DP were evaluated after remineralization and acid challenge. Characterization studies confirmed the presence of pure phase apatite. HRTEM confirmed the nanometric particle size of os-nHAp. MTT assay results showed that all the tested materials exhibited >80% cell viability when tested up to a concentration of 100 µg/mL. The results demonstrated a significantly higher mean percentage of TO, DoP, and lesser mean DP after remineralization in groups 1, 2, and 3 (p < 0.05). After the acid challenge, group 3 showed a significant reduction in TO and DoP, and increased DP (p < 0.05). However, no such changes were observed in groups 1 and 2. Within the limitations of this study, it can be concluded that os-nHAp and PA/os-nHAp could serve as potential and durable therapeutic agents in the treatment of dentin hypersensitivity.

Influence of varying dry air temperatures on postoperative sensitivity, penetration depth, and push-out bond strength of an ethanol/water-based adhesive: An in vivo double-blind clinical trial and in vitro analysis.

Background: Incomplete monomer infiltration into the etched dentin causes postoperative sensitivity (POS) with total-etch adhesives. Increasing the temperature of the air to dry the adhesive has shown to improve its infiltration into the dentin. Aims: The aim of this research is to evaluate the effectiveness of dry air temperatures of 15°C ± 5°C and 50°C ± 5°C on the POS, depth of penetration, and bond strength of an ethanol/water-based etch-and-rinse (ER) adhesive under in vivo and in vitro conditions. Methods: Forty-four premolars from 11 patients scheduled for orthodontic extraction were allocated into cold air (Group 1) and warm air (Group 2) groups using a split-mouth design. A 2 mm × 2 mm × 2 mm cavity was prepared on the middle third of the buccal surface of the teeth, acid etched, and two coats of an ethanol/water-based adhesive resin mixed with 0.1% rhodamine B was applied for 10 s. A dental air gun customized to deliver warm and cold air was used to dry the adhesive prior to its light polymerization. The cavities were restored with resin composite incrementally. POS was assessed using visual analog scale at 24 and 72 h using cold test. The teeth were atraumatically extracted and analyzed for depth of adhesive penetration using confocal laser scanning microscope (n = 11) and push-out bond strength (n = 11). Statistical Analysis Used: The data were analyzed using sample t-test and Wilcoxon signed-rank test (P < 0.05). Results: A significantly lower POS and greater adhesive penetration into the dentin was observed in the warm air group compared to cold air (P < 0.05). No significant difference could be elicited between the push-out bond strength of both the groups (P > 0.05). Conclusions: Warm air alleviated POS and improved the penetration of an ethanol/water-based ER adhesive into the dentin.

Characterization of nano-hydroxyapatite incorporated carboxymethyl chitosan composite on human dental pulp stem cells.

AIM: To compare the odontogenic differentiation potential of a composite scaffold (CSHA) comprising of nano-hydroxyapatite (nHAp) and carboxymethyl chitosan (CMC) with Biodentine on human dental pulp stem cells (hDPSCs). METHODOLOGY: A CSHA scaffold was prepared through an ultrasonication route by adding nHAp and CMC (1:5 w/w) in water medium followed by freeze-drying. Physicochemical characterization was achieved using scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. In-vitro bioactivity and pH assessments were done by soaking in simulated body fluid (SBF) for 28 days. The angiogenic and odontogenic differentiation abilities were assessed by expression of vascular endothelial growth factor (VEGF) and Dentine sialophosphoprotein (DSPP) markers on cultured hDPSCs by flow cytometry and RT-qPCR at 7, 14 and 21 days. Cell viability/proliferation and biomineralization abilities of CSHA were compared with Biodentine by MTT assay, alkaline phosphatase (ALP) activity, Alizarin Red Staining (ARS) and osteopontin (OPN) expression on hDPSCs following 7 and 14 days. Data were statistically analysed with Kruskal Wallis and Friedman tests as well as one way anova followed by appropriate post hoc tests (p < .05). RESULTS: Characterization experiments revealed a porous microstructure of CSHA with pore diameter ranging between 60 and 200 µm and 1.67 Ca/P molar ratio along with the characteristic functional groups of both HAp and CMC. CSHA displayed bioactivity in SBF by forming apatite-like crystals and maintained a consistent pH value of 7.70 during 28 days' in vitro studies. CSHA significantly upregulated VEGF and DSPP levels on hDPSCs on day 21 compared with day 7 (p < .05). Further, CSHA supported cell viability/proliferation over 14 days like Biodentine with no statistical differences (p > .05). However, CSHA exhibited increased ALP and ARS activity with an intense OPN staining compared with Biodentine after 14 days (p < .05). CONCLUSION: The results highlighted the odontogenic differentiation and biomineralization abilities of CSHA on hDPSCs with significant VEGF and DSPP gene upregulations. Further, CSHA exhibited enhanced mineralization activity than Biodentine, as evidenced by increased ALP, ARS and OPN activity on day 14. The nHAp-CMC scaffold has the potential to act as an effective pulp capping agent; however, this needs to be further validated through in-vivo animal studies.

Calcium hydroxide and niobium pentoxide treatment effects before MTA placement.

The aim of this study was to evaluate the effect of calcium hydroxide (CH) and niobium pentoxide (NP) pretreatment on pH, dentin microhardness and sealing of Mineral Trioxide Aggregate (MTA; Angelus). The pH of CH, NP and CH-NP (3:1) was evaluated in neutral and acidic simulated tissue fluid over 28 days. The Vickers microhardness was measured in forty 4 mm coronal root slices filled with pretreatment materials stored in medium for 1, 7, 28 days. Forty 10 mm roots were packed with pretreatment materials, irrigated after 24 h, then a 3 mm MTA plug was placed. Sealing ability was evaluated after 7 days using fluid filtration method. Statistics was performed using ANOVA and post hoc Tukey HSD tests. Addition of NP to CH maintained the alkalinity of CH, increased the microhardness of root dentin and reduced the microleakage. CH-NP can be effectively used as a pretreatment medicament in root canals requiring placement of MTA under acidic conditions.

Fracture Resistance of Endodontically Treated Premolars Restored with Flowable Short Fibre-Reinforced Resin Composite-An In Vitro Study.

OBJECTIVE: This in vitro study aimed to evaluate the fracture resistance of endodontically treated premolar teeth restored with flowable short fibre-reinforced resin composite (FSFRRC) at varying depths within the root canals. METHODS: Fifty freshly extracted human single-rooted premolars were divided into 5 Groups (n=10), Group I (IN) intact teeth, Group II (P) restored coronally with resin composite only, Group III, IV and V (FSFRRC2, FSFRRC4, FSFRRC6) based on post space preparation to the respective depths of 2, 4 and 6 mm. Root canal treatment was performed for all the samples of Group II, III, IV, V and the teeth were decoronated 2 mm above cementoenamel junction. Following decoronation, post space preparation was done to the depths of 2, 4, and 6 mm (Group III, IV, V). Teeth were restored with FSFRRC (Groups III-V) intra-radicularly and coronally sealed using resin composite. All the teeth were subjected to fracture strength test using Universal testing machine, and mode of failure was analysed. Kruskal-Wallis test followed by Dunn Post-hoc test was conducted for statistical analysis. Statistical significance was set at P<0.05. RESULTS: All FSFRRC groups showed higher fracture resistance than teeth restored only with resin composite. FSFRRC4 and FSFRRC6 showed significantly (P<0.05) higher fracture resistance than intact teeth and other experimental groups. CONCLUSION: Intra-radicular placement of FSFRRC increased the fractured resistance significantly and may serve as a promising alternative to conventional post systems to rehabilitate endodontically treated teeth.

Effect of 5% Carbohydrate Derived-Fulvic Acid on Smear Layer Removal and Root Dentin Microhardness - An In Vitro study.

OBJECTIVE: To compare the ability of 5% carbohydrate derived-fulvic acid (CHD-FA) with 17%ethylenediamine tetraaceticacid (EDTA) on smear layer removal when used as a final irrigant, and to assess their effect on root dentin microhardness. METHODS: A total of 56 single-rooted human mandibular premolars were decoronated to obtain standardized root length of 12 mm. Canal patency was established using 10 size K-file, working length was determined. Based on the irrigation regimen, samples were assigned into three groups; 17% EDTA, 5% CHD-FA and distilled water (control). The canals were instrumented with Protaper till F3 size. A standardized volume of 5 mL of each testing solution was used for 1 min. Roots were longitudinally split into two halves with one half of the samples for SEM analysis to evaluate the smear layer removal at coronal, middle, and apical thirds of root dentin. The other halves of the samples were subjected to Vickers microhardness testing. The data was statistically analyzed using Kruskal Wallis and Post Hoc test (P<0.05). RESULTS: 5% CHD-FA and 17% EDTA showed significant smear layer removal at all levels compared to distilled water (P<0.05). In the apical third, 5% CHD-FA showed significantly increased smear layer removal than EDTA (P<0.05). Microhardness testing of apical third showed significantly lesser reduction in microhardness for CHD-FA than EDTA (P<0.05). CONCLUSION: 5% CHD-FA could be a promising final irrigant for smear layer removal with decreased microhardness reduction on root dentin compared to 17% EDTA.